After defeat to UKIP in Clacton, and with the prospect of defeat to UKIP in Rochester, David Cameron has discovered two new ways to scrap with Brussels. Kapow! There’s his firmer emphasis on restricting European migration. Bam! And now there’s his resistance in the face of the EU’s budget demands. It’s going to be a knockout clash, make no mistake.

But whose corner is Angela Merkel in? Increasingly, it seems, the answer is: not Cameron’s. When it comes to the EU budget, she’s said to have been blunt and unsympathetic, telling our Prime Minister that the bill for another £1.7 billion “should have been expected”. When it comes to European migration, today’s Sunday Times (£) reports her as saying that “Germany will not tamper with the fundamental principles of free movement in the EU.” Uh-oh.

The German Chancellor’s views are not an unimportant part of the equation. Once, she was regarded as the powerbroker who would help Britain return some its own powers back from Europe. Downing Street hailed her interventions on migrant benefits. But now relations are much frostier. Disagreements over the elevation of Jean-Claude Juncker haven’t helped.

It’s tempting to say that Cameron is a victim of Merkel’s domestic problems – and, to some extent, that’s true. She currently faces the binary threat of Alternative für Deutschland and of Germany’s economic sluggishness, and she’s adopted an unyielding approach to both. Alternative für Deutschland and its euroscepticism have been attacked by Merkel’s allies as xenophobic and dumb. Calls for looser fiscal and monetary policies in Germany and across Europe have, as I explained last month, been dismissed out of hand. This is not a good time for the German Chancellor to start treating certain countries, such as Britain, as special cases. From her perspective, we must all walk the line.

But Cameron may not be helping himself with his recent angrier rhetoric and action. The political case for opposing Europe’s demands is clear – James Forsyth explains it, and the “nuclear option” of blocking the Eurozone’s self-help measures, very well in today’s Mail on Sunday. But what if, by doing so, the Tory leader alienates those, like Merkel, who could help him secure the broader change he wants? It’s yet another unforgiving variable in the situation that Mark described on Friday. Viel Glück, Prime Minister.